#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;
#define rep(i, a, b) for (int i = (a); i <= (b); i++)
#define per(i, a, b) for (int i = (a); i >= (b); i--)
#define endl '\n'
const int N = 2e5 + 5;

int n, m, s;
int a[N];

void solve() {
  cin >> n >> m >> s;
  ll x = ((n - 1) % s + 1) * ((n - 1) / s + 1);
  ll y = ((m - 1) % s + 1) * ((m - 1) / s + 1);
  cout << x * y << endl;
  return;
}
int main() {
  ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
  int t;
  t = 1;
  while (t--) solve();
  return 0;
}